Not many shinobi can use Rasengan, but these are the ones that can along with a few that just might be able to in the future.
The Rasengan in one of the most iconic Jutsu in Naruto that's been passed down from generations in Konohagakure. This Jutsu allows the user to manifest a ball of chakra that spins at extremely high speed and generates enough power to rip through whatever it touches. Due to it being so incredibly powerful, the Rasengan can be classified as an A-Rank Jutsu.)
Although it is widely known to be an incomplete Jutsu, it is undeniably one of the most used techniques in the series. Unsurprisingly, only a few shinobi have the ability to learn and create the Rasengan, and even fewer have the potential to learn it.
10. Minato Namikaze
Minato Namikaze was Konohagakure's Fourth Hokage. Also renowned as the Yellow Flash, it was Minato who created the Rasengan at some point in his life. This technique was used extensively by him since it didn't take long to prepare and could be used in conjunction with the Flying Thunder God as well.
Furthermore, Minato tried to add his nature transformations to the Rasengan as well, knowing it was an incomplete Jutsu. Unfortunately, he died before he could accomplish this. Nonetheless, his usage of this technique made him one of the most feared shinobi in the series.
One of the Legendary Sannin and the sensei of Minato's team, Jiraiya was one of Konoha's mightiest shinobi. Said to be a master of multiple Jutsu, Jiraiya also possessed the ability to use the Rasengan. The Rasengan was taught to him by his student, Minato Namikaze, who he described as a once-in-a-generation prodigy.
Akin to Minato, Jiraiya relied on this Jutsu quite a lot, and with time, it became his go-to technique. Jiraiya's skill with this Jutsu was such that he could magnify its size according to his liking and his Rasengan was said to be capable of tearing through mountains when unleashed.
8. Can Learn: Sarada Uchiha
The daughter of Konoha's legend Sasuke Uchiha, Sarada has inherited the powers of the Sharingan from her father. Having awakened a fully-matured Sharingan recently, Sarada's visual prowess is sure to have heightened. What's more, Sarada has already displayed the ability to be able to copy Jutsu before and doing the same with the Rasengan shouldn't be too hard for her.
If Kakashi Hatake could copy the Rasengan with his Sharingan, there's no reason to doubt whether Sarada should be able to do the same with hers. Furthermore, Sarada Uchiha is an admirer of the Seventh Hokage, Naruto Uzumaki. Learning this Jutsu could be her way of paying homage to her idol.
7. Kakashi Hatake
One of Minato Namikaze's students, Kakashi was revealed to be a user of the Rasengan as in Naruto Shippuden. Although the Copy Ninja doesn't rely on it as much as the others, he's certainly one of its strongest users. It remains unknown how Kakashi learned this Jutsu, or who taught it to him, but it is speculated that it has to do with his Sharingan, which grants him the power to copy Jutsu at will, as long as they're not Kekkei Genkai or Hiden abilities. Kakashi relies on the Raikiri instead of the Rasengan, which he created while attempting to infuse his chakra nature into the Rasengan.
6. Naruto Uzumaki
The protagonist of the series, Naruto Uzumaki was taught how to use the Rasengan by none other than Jiraiya, his master. Essentially, Jiraiya passed Minato's legacy on to his son by having Naruto learn the Rasengan. What's more, Naruto was even able to add his nature transformation to the Jutsu, which led to the creation of the Rasenshuriken.
Evidently, he did what Minato Namikaze couldn't, and completed the Rasengan. Throughout the Naruto series, the yellow-haired ninja is seen as its most extensive user, even managing to create multiple forms of the said technique.
5. Konohamaru Sarutobi
Konohamaru Sarutobi is the grandson of Konoha's Third Hokage, Hiruzen Sarutobi, and the nephew of Asuma. Being Naruto Uzumaki's apprentice, Konohamaru was taught the Rasengan prior to the Pain arc in the series. Just like Naruto, Konohamaru initially relied on using a shadow-clone to create this Jutsu, although, over the years, his control over it has refined to the point where he doesn't need to rely on one anymore.
Konohamaru also managed to add his Wind Release nature to the Rasengan, giving rise to Wind Release: Rasengan, a much stronger variant of the regular Rasengan.
4. Can Learn: Kawaki
Kawaki was properly introduced in the Boruto manga not so long ago. Since then, he's gone on to become a family member of Naruto Uzumaki, and also one of his own students. Under Naruto, Kawaki had managed to learn techniques such as the Shuriken Jutsu. Although the two haven't trained together in a while, they might get to do so again in the future.
Therefore, Kawaki learning Naruto's signature Jutsu isn't totally out of the question. In fact, it would make a lot of sense if Kawaki learns how to use chakra and eventually, create the Rasengan as well.
3. Boruto Uzumaki
Naruto Uzumaki's son and the protagonist of the Boruto: Naruto Next Generations series, Boruto Uzumaki is hailed as a prodigious shinobi. Being able to use three nature types as a Genin, it's no surprise that Boruto had it in him to learn the Rasengan. Under the guidance of Konohamaru Sarutobi, he successfully learned its usage.
Furthermore, he managed to add his nature to the Rasengan subconsciously, leading to the creation of Lightning Release: Vanishing Rasengan. Boruto's usage of this Jutsu was powerful enough to hurt Momoshiki Otsutsuki, a godly figure in the series. With time, he's only going to get better.
2. Kashin Koji
Kashin Koji is one of the members of Kara who has an enigmatic persona about him. Said to have some connection to Konohagakure, Kashin Koji is, surprisingly, able to use the Rasengan. How or when he learned this technique isn't known yet, but fans expect it to be revealed very soon. In his fight against Konohamaru Sarutobi, Kashin Koji was able to summon a giant frog from Mount Myoboku and use the Rasengan to counter Konohamaru's Jutsu.
As such, fans have speculated that the true identity of Kashin Koji is none other than Jiraiya himself. What else Kashin Koji is capable of remains to be seen, but he's, undoubtedly, one of Boruto's most intriguing characters.
1. Can Learn: Himawari Uzumaki
Himawari is the daughter of Naruto and Hinata Uzumaki. Like Boruto, Himawari appears to have a lot of potential in the bag, and she's managed to awaken the Byakugan on more than one occasion now. Although Himawari isn't focused on in the series as much, she's likely to grow up to become a decent Kunoichi in the coming years.
With the Kekkei Genkai of the Byakugan already at her disposal, Himawari could go a step further and learn more Jutsu. Just like Boruto, she could end up mastering the Rasengan as it serves as his father's legacy.